Add improved documentation for `pecan.request` and `pecan.response`.
Add improved documentation for `pecan.request` and `pecan.response`.

Change-Id: I6f27e5a352000758b959f70d19261389a3ea97b7
Closes-Bug: 1276869

jdandrea/pecan,pecan/pecan,ryanpetrello/pecan,jdandrea/pecan,pecan/pecan,StackStorm/pecan,ryanpetrello/pecan,jimrollenhagen/pecan,jimrollenhagen/pecan,StackStorm/pecan